Cuckoos

Cuckoos, coucals, anis, malkohas, and roadrunners are approximately 127 species of birds that make up the family Cuculidae. These birds are mostly tropical in distribution, but some species also breed in the temperate zones. Many species are parasitic breeders, laying their eggs in the nests of other species of birds. Species of the cuckoo family occupy a great diversity of habitats, ranging from desert to temperate and tropical forests.

The cuckoos vary greatly in size, with the range of body length being about 6–27.5 in (16–70 cm). These birds tend to have an elongated body, a rather long neck, a long tail, rounded wings, and a stout, down-curved beak. The basal coloration of the body is generally a brown, grey, or black hue, often with barring of the underparts or a white breast. Males and females are similarly colored, but juveniles are generally different.

A large number of species in the cuckoo family are nest-parasites. Instead of constructing their own nests, these parasitic birds seek out and discover nests of other species, and then lay an egg inside. If the host is of a similar size as the parasitizing cuckoo, then several eggs may be laid in the nest, but on separate days. Only one A greater roadrunner. Maslowski/Photo Researchers, Inc. Reproduced by permission. egg is laid if the cuckoo is substantially larger than the host, as is often the case. The female cuckoo may also remove any pre-existing eggs of the host species.

The host birds commonly do not recognize the foreign egg, and incubate it as if it was their own. The host then cares for the parasitic hatchling until it fledges, and often afterwards as well. In most cases, the host species is much smaller than the parasite, and it is quite a chore to feed the voracious young cuckoo. The young cuckoo commonly hatches quite quickly and ejects the unhatched eggs of the host from the nest, or it ejects or otherwise kills the babies of the host. Once their nest is discovered by a female cuckoo, the parasitized hosts are rarely successful in raising any of their own young under these sorts of circumstances.

Male cuckoos maintain a breeding territory, largely using a loud and distinctive, often bell-like call. Interestingly, females of the nest-parasitic species of cuckoos also maintain a territory, independent of that of males of their species. In this case, the defended area involves foraging habitat for the discovery of nests of other species, rather than for access to females, as in the case of the male cuckoos.

Many species of cuckoos that breed in the temperate zones undertake a long-distance migration between their breeding and non-breeding ranges. This is true of species breeding in the Northern Hemisphere, which winter to the south, and also of species breeding in the Southern Hemisphere, which winter to the north. For example, the shining cuckoo (Chalcites lucidus) of temperate New Zealand migrates across open waters of the Pacific Ocean, to winter in tropical habitats of the Bismarck Archipelago and Solomon Islands off New Guinea.

Most species in the cuckoo family feed mostly on insects and other arthropods. Some of the smaller species of cuckoos will eat the hairy caterpillars of certain types of moths and butterflies. Hairy caterpillars are often an abundant type of food, in part because they are rejected by most other types of birds, which find the hairs to be irritating and distasteful. Some of the larger species of cuckoos will also feed on lizards, snakes, small mammals, and other birds.

The best-known species in the Cuculidae is the Eurasian cuckoo (Cuculus canorus), which breeds widely in forests and thickets of Europe and Asia. This species is the best-studied of the nest-parasites, laying single eggs in the nests of a wide range of smaller species. Although the egg of the Eurasian cuckoo is usually larger than those of the parasitized host, it is often colored in a closely similar way to the host species. Individual Eurasian cuckoos are known to have laid single eggs in as many as 20 nests of other species in one season. The call of the male Eurasian cuckoo is the famous, bi-syllabic: "cuck-coo," a sound that has been immortalized in literature and, of course, in cuckoo-clocks. Northern populations of this species migrate to Africa or southern Asia to spend their non-breeding season.

Two familiar cuckoos of North America are the yellow-billed cuckoo (Coccyzus americanus) and the black-billed cuckoo (C. erythrophthalmus). Both of these species breed in open woodlands and brushy habitats. The yellow-billed cuckoo ranges over almost all of the United States, southern Ontario, and northern Mexico, and winters in South America. The black-billed cuckoo ranges over southeastern North America, and winters in northwestern South America. This species is most abundant in places where there are local outbreaks of caterpillars. Both of these species build their own nests and raise their two to four babies. However, both species are occasional nest-parasites on other species, including each other.

A much larger American species is the greater road-runner (Geococcyx californianus), a terrestrial bird of dry habitats in the southwestern United States and Central America. The greater roadrunner is the largest cuculid in North America. This species commonly feeds on lizards and snakes, including poisonous rattlesnakes. The greater roadrunner is not a nest-parasite. Roadrunners are fast runners, although not so fast and intelligent as the one that always gets the better of Wile E. Coyote in the famous Warner Bros. cartoons.

Two species of anis breed in North America, the smooth-billed ani (Crotophaga ani) of southern Florida, and the groove-billed ani (C. sulcirostris) of southern Texas. These species also occur widely in Central and South America, and on many Caribbean islands. Anis build communal, globular, stick-nests in trees. Each of the several cooperating pairs of anis has its own nesting chamber, and incubate their own eggs. Both parents share in the brooding of the eggs and raising of the young, although there is some degree of cooperative feeding of young birds within the commune. Anis have home ranges, but because of their communal nesting, they do not appear to defend a territory.

The coucals are relatively large birds of Africa, South and Southeast Asia, and Australasia. Rather weak flyers, coucals are skulking birds that occur near the edges of scrubby and wooded habitats. The greater coucal or crow-pheasant (Centropus sinensis) of southern and southeastern Asia is a large (20 in [53 cm] body length), black, widespread species. Coucals build their own large globular nest of grasses and leaves near the ground in dense vegetation. The male and female share the incubation and rearing of the three to five babies.